Data-reading image capture apparatus, camera, and method of use

CROSS REFERENCE TO RELATED APPLICATIONS

Reference is made to commonly assigned co-pending U.S. patent applications Ser. No. 08/931,575 and filed in the names of Peter Soscia, Jeffrey Small, Thomas Reiter; Ser. No. 08/959,041 and filed in the name of Peter Soscia; Ser. No. 08/959,036 and filed in the name of Peter Soscia; Ser. No. 09/019,506 and filed in the name of Peter Soscia Ser. No. 09/099,627, now abandoned and filed in the names of Peter Soscia, Jeffrey Small, Thomas Reiter; Ser. No. 09/099,616 U.S. Pat. No. 6,441,921 and filed in the name of Peter Soscia.

FIELD OF THE INVENTION

The invention relates to image capture apparatus including photographic cameras and more particularly relates to a data-reading image capture apparatus, a data-reading camera, and a method of using the camera.

BACKGROUND OF THE INVENTION

U.S. patent application Ser. No. 08/931,575, filed Sep. 16, 1997, which is hereby incorporated herein by reference, discloses the use of a printed invisible encodement on a photographic image to record sound information. The encodement is read by illuminating using a beam of invisible electromagnetic radiation that is subject to modulation by the encodement. The resulting encodement image is captured, decoded, and played back. The photographic image on which the encodement is printed is originally captured using a camera. The invisible radiation image is captured using a reader that is capable of capturing only invisible images within a selected band. (The term “band” is used herein to refer to one or more contiguous or non-contiguous regions of the electromagnetic spectrum. The term “invisible” is used herein to describe material which is invisible or substantially invisible to the human eye when viewed under normal viewing conditions, that is, facing the viewer and under sunlight or normal room illumination such as incandescent lighting.) The invisible image is produced by development of a photographic emulsion layer, inkjet printing, thermal dye transfer printing or other printing method. The encodement is a one or two-dimensional array of encoded data.

Digital cameras and other visible image capture apparatus utilize a visible light sensitive electrical device. At least some of these light sensitive devices are also sensitive to invisible radiation. Charge coupled devices (CCD's) are so sensitive to infrared radiation that attenuation is required during capture of the visible light image. This is generally accomplished by permanently mounting an infrared blocking filter in the optical system of the camera or other capture device.

It would thus be desirable to provide for capture of visible images and images of invisible encodements without the need for both a camera and a separate encodement reader.

SUMMARY OF THE INVENTION

The invention is defined by the claims. The invention, in its broader aspects, provides a data-reading image capture apparatus, camera, and method of use. The capture apparatus has a digital image detector sensitive to a band of visible radiation and a band of invisible electromagnetic radiation. An optical system, in the capture apparatus, focuses the bands of electromagnetic radiation on the image detector. An image separator is disposed in the capture apparatus, in operative relation to the digital image detector and optical system. The image separator is switchable between an image capture state and a data reading state. The image separator is attenuative for the band of invisible radiation and transmissive for the band of visible radiation in the image capture state. The image separator is attenuative for the band of visible radiation and transmissive for the band of invisible radiation in the data reading state.

It is an advantageous effect of at least some of the embodiments of the invention that a data-reading image capture apparatus, a data-reading camera, and a method of using the camera are provided which allow for capture of visible images and images of invisible encodements without the need for both a camera and a separate encodement reader.

BRIEF DESCRIPTION OF THE DRAWINGS

The above-mentioned and other features and objects of this invention and the manner of attaining them will become more apparent and the invention itself will be better understood by reference to the following description of an embodiment of the invention taken in conjunction with the accompanying figures wherein:

FIG. 1 is a semi-diagrammatical perspective view of an embodiment of the camera of the invention. The filter holder is in a visible image capture position.

FIG. 2 is the same view as FIG. 1, but the filter holder is shown in a data-reading position.

FIG. 3 is a diagrammatical view illustrating use of the camera of FIG. 1 to capture a visible image and record sound data.

FIG. 4 is a diagrammatical view illustrating use of the camera of FIG. 1 to read invisible printed data on a photographic print and playback recorded sound.

FIG. 5 is a graph of percent maximum transmittance vs. wavelength for an infrared blocking filter suitable for use with the camera of FIG. <b>1</b>.

FIG. 6 is a graph of percent maximum transmittance vs. wavelength for an infrared band pass filter suitable for use with the camera of FIG. <b>1</b>.

FIG. 7 is a semi-diagrammatical view of another embodiment of the camera of the invention.

FIG. 8<i>a </i>is a partial front view of still another embodiment of the camera of the invention. The filter holder is shown in a visible image capture position. The secondary filter mount is shown in a close-up filter position.

FIG. 8<i>b </i>is the same view as FIG. 8<i>a</i>, except the secondary filter mount is in a normal lens position. The filter holder is shown in the visible image capture position.

FIG. 8<i>c </i>is the same view as FIG. 8<i>a</i>, except the filter holder is in a data-reading position. The secondary filter mount is in the close-up filter position.

FIG. 9 is a diagrammatical view showing use of another embodiment of the camera of the invention to read invisible printed data on a photographic print and playback recorded sound.

DETAILED DESCRIPTION OF THE INVENTION

The data-reading image capture apparatus <b>10</b> is a camera, scanner, or other imager that has an exposure system <b>12</b> that can capture both a visible radiation image and a second image, separate from the visible radiation image. The captured second image is invisible; that is, the second image is formed by radiation in a band outside the visible spectrum. The second image is reflection, transmission, or luminance from an invisible layer that overlies a visible image. The visible image can be limited to an underlying substrate without information content, but ordinarily would be printed information, in the form of pictorial information, text or other alphanumeric information, or non-alphanumeric indicia. The nature, content, and manner of preparation of the printed image is not critical. The invisible layer can simply be a pictorial image or indicia, but is preferably in the form of a data encodement. For convenience, the capture of the invisible second image is also sometimes referred to herein by the term, “data reading” and similar terms. For example, a camera of the invention can be used to both photograph a subject and to read data invisibly imprinted on a photograph print. (This is illustrated in FIGS. 4 and 9 as a sheet <b>14</b> bearing a visible printed image <b>16</b> of a pair of trees. The word “DATA” appears in dashed lines, to represent the invisible encodement <b>18</b>.) The data in the encodement can include subject specific information, such as sound recorded when the picture was taken, for playback at the time of viewing the photographic print or other use. The form of the encoded data is not critical to the invention. For example, the encodement can be in accordance with Standard PDF 417 and the LS49042D Scanner System marketed by Symbol Technologies, Inc., of Holtsville, N.Y.; or the encodement scheme marketed as Paper Disk by Cobblestone Software, Inc., of Lexington, Mass.

The invention is discussed herein generally in terms of a camera <b>10</b>, that is, a portable general purpose image capturing apparatus; but it will be understood that equivalent features are intended for other data-reading image capture apparatus, such as flatbed and media transport scanners. The invention is also discussed herein generally in terms of a visible radiation image and an invisible encodement. The visible image can include a small percentage of invisible radiation (also referred to herein as an “invisible component”). Similarly, the invisible encodement is preferably fully invisible under ordinary viewing conditions, but can include a small percentage of visible radiation (also referred to herein as a “visible component”). An invisible component of the visible image is a inconsequential unless the component is in the same radiation band as the invisible encodement. In that case, the invisible component can act as background noise and reduce the signal to noise ratio of the invisible encodement. The amplitude of the invisible component should be insufficient to measurably degrade a digital image produced from the invisible encodement when the invisible encodement is read. Any visible component of the invisible encodement should, preferably, be imperceptible to the viewer under ordinary viewing conditions; but slight degradation of the image may be acceptable under some conditions.

The invisible encodement can absorb the invisible radiation or can reflect and/or emit the invisible radiation. The frequency range or ranges of the invisible radiation is dependent upon the characteristics of the material used for the invisible encodement. Depending upon the material, infrared radiation or ultraviolet radiation or both can be used. High frequency ultraviolet radiation and radiation of higher frequency is not preferred in current embodiments for reasons of safety. Infrared radiation is preferred over ultraviolet for the same reason.

Referring now to FIGS. 1-2, a camera <b>10</b> includes the exposure system <b>12</b>, a body <b>20</b> supporting the exposure system <b>12</b>, and a control interface accessible from the outside of the body <b>20</b> for controlling the exposure system <b>12</b>. The control interface includes a shutter button <b>22</b>. The exposure system <b>12</b> includes a capture unit <b>24</b> and an optical system <b>26</b> (illustrated in FIGS. 1-2 as a circle) that focuses electromagnetic radiation on the capture unit <b>24</b>.

The capture unit <b>24</b> includes a digital image detector <b>28</b> that is sensitive to a band of visible radiation and a band of invisible electromagnetic radiation. The digital image detector <b>28</b> is used to capture the invisible second image. The digital image detector <b>28</b> comprises one or more radiation-sensitive electrical devices which convert an impinging radiation beam into a digital image, that is, an electrical signal from which a two dimensional image can be reconstructed. It is currently preferred to use light-sensitive electrical devices that are sensitive to a broad band of radiation including all or most of the visible spectrum and a selected band of invisible radiation. For example, widely available charge coupled devices (CCD's) are sensitive to visible radiation and a broad band of infrared radiation. The light-sensitive electrical device can also be a charge injection device, a photodiode, a CMOS imager, or another type of photoelectric transducer.

The digital image detector <b>28</b> can include one or more two-dimensional light-sensitive electrical devices, or one or more two dimensional arrays of such devices, or one or more one-dimensional arrays of such devices. With one-dimensional arrays, the detector includes means, well known to those of skill in the art, for scanning the incident beam to provide a two-dimensional digital image. Two-dimensional devices are preferred over one dimensional devices and the use of single discrete devices is currently preferred over the use of arrays of smaller devices for reasons of image quality and ease of assembly. It is well known in the art to use a single two-dimensional capture device with a pixellated three-color filter for color visible image capture. It is also well known to use three two-dimensional devices with a beam splitter and individual colored filters. The use of the single two-dimensional capture device is preferred for reasons of economy. An example of a suitable digital image detector <b>28</b> comprises a single CCD, such as a charge coupled device marketed by Eastman Kodak Company of Rochester, N.Y. as Model No. KAF-6300. Lower resolution digital image detectors can also be used, such as a VGA (video graphics array) sensor having a resolution of 640 by 480 pixels. If desired, the camera of the invention can be prepared by modifying an existing digital camera, such as a DCS-210, marketed by Eastman Kodak Company of Rochester, N.Y., to add a filter holder (described in detail below).

The digital image detector <b>28</b> can be used for capture of the visible image. In this case, the digital image detector <b>28</b> is utilized for visible image capture in the same manner as in the various digital cameras well known to those of skill in the art. Alternatively, a visible image capture component <b>30</b> can be used. The visible image capture component <b>30</b> can be digital, using the same kinds of components as previously described for the digital image detector <b>28</b>; or can utilize photographic film, as shown in FIG. <b>7</b>. Suitable photographic film camera features, such as exposure, film metering, and film transport mechanisms, are well-known to those of skill in the art.

The exposure system <b>12</b> of the capture apparatus <b>10</b> includes an image separator <b>32</b>, for separating the visible light and invisible radiation images. The image separator <b>32</b> can be in the form of one or more digital computer programs or subroutines (hereafter “software”), or can be limited to physical features of the capture apparatus <b>10</b>, such as optical filters, or can combine physical features and software. Depending upon intended usage, the image separator <b>32</b> can switch automatically between visible image capture and data reading states or can be selectively alternated by the user. For a camera <b>10</b>, selective alternation by the user is preferred. The manner of alternating the states is not critical, but should not interfere with usage of the capture apparatus <b>10</b> in either state. For example, optical filters can be alternated by detachment and reattachment or, more preferably, by use of any of a wide variety of linear and rotary motion mechanisms to move the filters.

In the camera of FIG. 7, the image separator <b>32</b> is a mirror that, in a first position <b>32</b><i>a </i>(indicated by solid lines), directs light to the digital image detector <b>28</b>; and, in a second position <b>32</b><i>b </i>(indicated by dashed lines), directs light to photographic film or digital visible image capture component <b>30</b>. Suitable mirror mechanisms are well known to those of skill in the art, since similar mirror mechanisms are used in single lens reflex cameras. A fixed half-silvered mirror could also be used. The image separator <b>32</b> of FIG. 7 is not preferred since it is relatively complex and requires separate invisible and visible light detectors <b>28</b>,<b>30</b>, respectively.

In another embodiment of the invention, the image separator <b>32</b> uses one or more optical filters. This approach is simple and relatively inexpensive and is therefore currently preferred. Referring to FIGS. 1 and 2, in order to separate out the invisible image, the image separator <b>32</b> includes a data filter <b>36</b> attenuative for the band of visible radiation to which the digital image detector <b>28</b> is sensitive and transmissive for the band of invisible radiation. The image separator <b>32</b> also includes an image filter <b>38</b> attenuative for the band of invisible radiation and transmissive for the band of visible radiation. If the band of invisible information is infrared, then the data filter <b>36</b> is an infrared bandpass filter and the image filter <b>38</b> is an infrared blocking filter. Simplified absorption spectra for an infrared blocking filter and an infrared bandpass filter are shown in FIGS. 5 and 6, respectively. Examples of suitable optical filters are an infrared blocking filter, Model No. 58893, marketed by Oriel Corporation of Stratford, Conn.) and infrared bandpass filter, Model No. 54020, also marketed by Oriel Corporation.

The image and data filters <b>36</b>,<b>38</b> are interposed in operative relation to the detector <b>28</b>, alternately, for visible image capture and data reading, respectively. The image filter <b>38</b> can be optional if the capture component <b>30</b> uses photographic film for visible image capture; since ordinary color and black-and-white photographic films, under most conditions, do not absorb well outside the visible spectrum. Under some conditions, such as with high intensity ultraviolet exposure or infrared exposure and infrared film; the use of an image filter <b>38</b> would be required or highly desirable.

Referring to the embodiments shown in FIGS. 1-2, image and data filters <b>36</b>,<b>38</b> are each fixed to a filter holder <b>40</b> and are pivoted back and forth about an axis, by an actuator <b>42</b>, such as a servomotor or mechanical linkage or lever arm. Camera <b>10</b> includes an external selector <b>44</b> that is operatively connected to the actuator <b>42</b> (such as, wired in an appropriate circuit for the servomotor or physically joined) to move the filter holder <b>40</b> between image capture and data reading positions.

The camera or other image capture apparatus <b>10</b> can include a variety of other features for convenience and ease of use. Many cameras have a lens that does not focus well in the distance range which is likely to be used for data reading. In such a camera <b>10</b>, a close-up filter <b>46</b> (sometimes referred to as a “close-up lens”) shown in FIGS. 8<i>a</i>-<b>8</b><i>c</i>, can be provided so as to be interposable in the optical system (illustrated in FIGS. 8<i>a</i>-<b>8</b><i>c </i>by a cross indicating the position of the optical axis <b>26</b><i>a</i>) in tandem with the data filter <b>36</b>. The close-up filter <b>46</b> can be fixed to the data filter <b>36</b> or can be mounted so as to be required for use of the data filter <b>36</b> and optional with the image filter <b>38</b>. Referring to FIGS. 8<i>a</i>-<b>8</b><i>c</i>, a filter holder <b>40</b> includes the image filter <b>38</b> and the data filter <b>36</b>. The filter holder <b>40</b> is mounted to the camera body <b>20</b> and is movable between an upper position and a lower position, as indicated by double-headed arrow <b>48</b>, in FIGS. 8<i>a </i>and <b>8</b><i>c</i>, to alternately interpose the image filter <b>38</b> and data filter <b>36</b> in the optical system <b>26</b> of the camera <b>10</b>. A filter mount <b>50</b> is also joined to the body <b>20</b>. The filter <b>50</b> is movable, perpendicular to the directions of motion of motion of the filter holder <b>40</b>, between left and right positions. In the left position, a close-up filter <b>46</b>, mounted on the filter mount <b>50</b>, is interposed in the optical system <b>26</b>. In the right position, a normal window <b>52</b> is disposed over the optical system <b>26</b>. The normal window <b>52</b> allows the optical system <b>26</b> to function in a “normal” mode (subject matter at a moderate to long focusing distance). The normal window <b>52</b> can be an opening or can be part of the optical system <b>26</b>, that is, a “normal” lens, or can be an accessory, such as a protective window, an auxiliary filter (such as a sky or ultraviolet blocking filter) or the like. The filter mount <b>50</b> includes a stop <b>54</b> that allows use of the data filter <b>36</b> without the close-up filter <b>46</b>. (Blocked motions of the filter holder <b>40</b> and filter mount <b>50</b> are indicated by crossed-out double headed arrows <b>56</b>,<b>58</b> in FIGS. 8<i>b </i>and <b>8</b><i>c</i>, respectively. The stop <b>54</b> does not prevent use of the visible image filter <b>38</b> with either the close-up filter <b>46</b> or the normal window <b>52</b>. This permits the use of camera <b>10</b> to capture normal distance and close-up pictorial images. Camera <b>10</b> can also capture visible barcodes and the like, using the visible image filter <b>38</b> and close-up filter <b>46</b>.

Camera <b>10</b> can include an invisible radiation illumination source <b>60</b> for the band of invisible electromagnetic radiation, such as an infrared illuminator. Camera <b>10</b> can also include a visible light illumination source <b>62</b> for the visible image, such as a flash unit. A wide spectrum illuminator can be used instead of separate sources <b>60</b>,<b>62</b> for illumination for both visible image capture and data reading. Suitable illumination sources, power supplies and related features are well known to those of skill in the art. An example of an illumination source <b>60</b> usable for data capture is a commonly available infrared emitter with a peak wavelength at 880 nm, such as Part No. MTE2050-OH1 marketed by MarkTech Optoelectronics of Latham, N.Y. The camera or other image capture apparatus <b>10</b> can have a wide variety of other features present in known cameras and other capture apparatus.

FIG. 9 illustrates features and use of another embodiment of the camera <b>10</b> that includes a digital image separator <b>32</b>. The image separator <b>32</b> includes a selector <b>44</b> that can be manually alternated (illustrated by double-headed arrow <b>64</b>) by the user to change the image separator <b>32</b> between visible image capture and data reading states. For data reading, the user first switches to the appropriate state and then points the camera <b>10</b> at the target, that is, the visible image <b>16</b> bearing the invisible encodement <b>18</b>. This is done under ordinary lighting conditions of daylight or ordinary artificial illumination or some combination of the two. A controller <b>66</b> of a control and processing unit <b>68</b> receives a status signal from the selector <b>44</b> (via by control line <b>70</b>) and changes to the respective state. Controllers <b>66</b> in the form of microprocessors and other components of the control and processing unit <b>68</b> are well known to those of skill in the art.

The user then actuates camera <b>10</b>. The shutter button <b>22</b> (shown in FIGS. 1-2) can be used to actuate camera <b>10</b> or a separate button or switch (not shown) can be used to actuate camera <b>10</b> in the data reading state, if desired. The controller <b>66</b>, in response to the actuation, activates an invisible radiation illumination source <b>60</b> and causes the digital image detector <b>28</b> to capture an image of the target (symbolized in FIG. 9) by a broad arrow <b>71</b>) in a combination of the supplied invisible radiation and ambient lighting <b>72</b> (symbolized in FIG. 9 by a sun symbol.). The resulting extended spectrum image is stored in a first memory unit <b>74</b>. Before or after this capture, the controller <b>66</b> causes the digital image detector <b>28</b> to capture another image <b>71</b> of the target, while the invisible radiation illumination source <b>60</b> is deactivated. The resulting visible light only image is stored in a second memory unit <b>76</b>. These two capture events are illustrated in FIG. 9 by pairs of paths, each labelled “A” and “B” to sources of illumination and to and from memory storage units. Control lines <b>82</b> from the controller <b>66</b> link to switches <b>84</b> (logical or physical or a combination) for the alternate paths A and B.

The extended spectrum and visible light images are combined in a processor <b>78</b>. The processor <b>78</b> can be subject to a common controller <b>66</b> via a control line <b>86</b>. The visible light only image is subtracted from the extended spectrum image to provide an invisible radiation image which is processed as necessary to retrieve encoded information, and output. (The data output <b>88</b> is symbolized as a series of musical notes.) A digitized visible light image <b>90</b> (indicated by dashed lines) is also available and can be processed and output as desired. For visible image capture, the selector <b>44</b> is changed to the “B” position and only the “B” capture and processing path is utilized to provide a visible light only image <b>90</b>.

The digital image separator <b>32</b> is preferably used under conditions in which there is little invisible radiation in the ambient visible lighting. Under such conditions, an advantage in signal to noise ratio can be provided, relative to optical filters.

Camera <b>10</b> is used by first selecting for data reading or photography and adjusting the selector <b>44</b> to the appropriate state. When the visible image state is selected, the camera <b>10</b> is used for photography and, if desired, for recording of non-image data. Following capture, the captured image or images are processed (chemically or digitally) and visible depictions of captured visible light images are printed (optically or digitally). An invisible encodement of data, secondary to the visible image; can be printed on the photographic print. Since the encodement is invisible, all or part of the encodement can overlie the printed image. In the embodiment shown in FIGS. 3-4, sound or other input <b>92</b> (symbolized as a series of musical notes) is recorded contemporaneously with picture taking, using a microphone or other input device <b>94</b>, such that an invisible encodement of the sound can be printed on the front surface of a resulting photographic print.

When the data reading camera state is selected from the alternatives of the visible image state and the data reading camera state, camera <b>10</b> is configured to admit invisible radiation in a preselected band and filter out visible radiation. The invisible encodement <b>18</b> is illuminated with a beam of invisible radiation. The encodement <b>18</b> modulates the beam producing a transmitted or reflected image of the encodement, which is digitally photographed. The resulting digital image is processed by an output system resulting in a unit of digital data. The manner of processing to produce and later utilize the digital data is not critical to the invention. The output system can store the processed digital data, or transmit the digital data in some manner to a sound system or other output device <b>96</b> to playback all or part of the processed digital data to the user, or provide some combination of these functions, on an immediate or delayed basis. (Playback is illustrated in FIG. 4 by a symbol in the form of a series of musical notes.) Components to provide any or all of these functions are well known to those of skill in the art. For example, decodement methods and components are available for the encodement schemes previously mentioned.

The separation of digital data processing from storage, transmission, and display; is a matter of logical convenience in this explanation. It will be understood that digital data processing need not be limited to a single component and processing, control, storage, transmission, and display functions can be supplied by a variety of equipment in a variety of manners. For example, in the embodiments shown in FIGS. 3-4, the digital data is played back by a digital sound playback system through a speaker. Other audio or visual or textual information can be played back or displayed in a similar manner. The digital data can be used for control or archival purposes. Multiple uses can be made of the same unit of digital data.

The invention has been described in detail with particular reference to certain preferred embodiments thereof, but it will be understood that variations and modifications can be effected within the spirit and scope of the invention.